Eurnace and ventilator



c. B. SAWYER.

Hot Air Furnace. No. 25,279. Patented Aug. 30, 1859.

lwvenio UNITED STATES PATENT OFFICE.

CHARLES E. SAWYER, OF FITOHBURG, MASSACHUSETTS.

FURNACE AND VENTILATOR.

Specification of Letters Patent No. 25,279, dated August 30, 1859.

To all whom it may concern:

Be it known that I, CHARLES B. SAWYER, of Fitchburg, lVorcester county,in the Commonwealth of Massachusetts, have invented an Improved Furnaceand Ventilator; and I do hereby declare that the following is a full andexact description of its construction and operation, reference being hadto the accompanying drawings, and to the letters of reference markedthereon, so as to enable others skilled in the art to make and use myimproved furnace and ventilator.

Figure 1, of the drawings represents a vertical central section throughthe furnace,

and Fig. 2, a horizontal section on the line a, b, of Fig. 1.

The furnace is surrounded by two concentric metal cylinders P, Q, thecylinder Q, being of smaller diameter than the cylinder P, so as toleave a hollow space R, between the two cylinders which serves as a nonconductor of heat in regard to the warm air inside of cylinder Q. Twochambers I, A, are arranged one on top of and the other below the doublecylinder P, Q. The space S, within the cylinder Q, contains the radiatorX, firepot K, and ashpit T, one above the other.

Three or more warm air pipes G, are arranged around the firepot andradiator and inside of the cylinder Q. Their upper ends pass through thedouble wall Q, P, of the furnace and into the various rooms to be heatedby the furnace. Their lower ends open through the bottom of the furnaceinto the cold air chamber A and are provided with dampers V. The coldair chamber communicates with the outside air by means of a pipe B.

Fire fiues H, one to each of the warm air pipes G, pass from the firepot into and through the warm air pipes into the radiator X, the bottomof which latter is provided with a damper Y. A pipe F, passes from theradiator through chamber I, into the ventilating conductor 0. A passageZ, which leads from the fire pot through the double wall of the furnaceand which is provided with a door D, serves for the introduction of thefuel.

U, is the grate in the bottom of the fire pot.

Some kindlings being placed upon the grate, the coal is turned inthrough the door D, upon the kindlings after which the door D, is closedand damper or door IV, in the ash box T, under the grate opened. Thekindlings being now fired the draft through the fire flues H, will causethe flame and heat to ascend through the coal so as to cause it toignite, after which the door or damper IN, is closed, and the damper D,in the door D, is partially opened. In this way all air is shut out fromingress below the coal, and consequently the fresh air to supportcombustion must pass in through the door D, and then down through thecoal and out and up the fire and draft flue H, so that the most intenseheat of the burning coal will be on or about on a line with the upperedge of the draft flue H, where they leave the fire pot K, as indicatedin red color in the drawings. Now as the air enters the fire pot throughthe door D, it seeks or flows toward the inside of the fire pot asindicated by black arrowsinstead as some would suppose down directlythrough the coal. It will therefore be seen that the highly carbonizedgas which escapes or is evolved by the gradually heating of the coal inthe fire pot above the fines H, and before it becomes ignited will to agreat extent rise through the coal, until it comes in contact with thefresh air when it will be turned and carried toward and down the sidesof the fire pot as indicated by blue arrows. The damper Y, whichseparates the gas or combustion chamber S, from the radiator X, is nowslightly opened so as to cause a slight draft from the chamber S, upthrough the radiator X, pipe F, and ventilating con ductor O, inconsequence of which the highly carbonized gas above mentioned flowstoward the little holes 0, arranged around and through the fire potimmediately above the fire fiues H, and burns freely as it passes out ofsaid holes 0, into the space S. Thus all the gases generated from thecoal in the firepot are burned and serve to heat the air in the space S,either directly by burning through the holes 6, as described, orindirectly by heating the surface of the fire pot with which the air inthe chamber S, is in contact. This volume of heated air surrounds thewarm air pipes G, and thus serves to heat the air passing through saidpipes, which, however, is more directly heated by means of the fireflues H, which pass from the fire pot through the pipes G, into theradiator.

Pipes J lead from openings in the floors of the rooms into theventilating chamber I, and the vitiated air passes from the roomsthrough said pipes J, into the chamber I, and out into the ventilatingconductor 0, as shown in dotted arrows.

If there Were none of the holes 0, arranged around and through the firepot immediately above the fire flues H, the highly carbonized gasgenerated as above mentioned, would follow the impulse of the strongdraft up through the fire fiues H, and Would escape unburned. But in myfurnace this gas passes through the holes 0 into space S, before itreaches the mouths of the fire fiues H, and is burned in the space S,under a slight draft, so as to effect a thorough com- 15 bust-ion.

Having described my improved furnace and ventilator What I claim thereinas new and desire to secure by Letters Patent, is-

Providing the fire pot With a series of 20 small holes or openings 0,substantially as and for the purposes set forth.

CHARLES B. SAWYER.

Witnesses:

O. STAFFORD CHAMBERLAIN, NATHL W001).

